Rock pulverizer



Jurn e 26, 1 923.

C. S. WILLIS ROCK PULVERIZER Filed May 29, 1922 3 Sheets-Sheet 1 3 m Car/ 5. )V/V/fs.

Patented June 26, 1923.

PATENT OFFICE.

, CARL S. WILLIS, OF BELLINGHAM, WASHINGTON.

nook 'rULvEnIzER.

Application filed may 29, 1922. Serial No. 564,373. 7

To all whom it may concem:

Be it known that I, CARL S. WILLIS, citizen of the United States residing at Bellingham, in the county of Whatcom, in the State of Washington, have invented certain new and useful Improvements in Rock Pulverizers, of which the following is a specification.

This invention relates to a rock pulverizer and is of that class known as a rod mill wherein the crushing of the rock is effected by the tumbling of a series of heavy metal rods over one another within a rotatable container,

The improvements are directed to the attainment of a percussive action of the rods on the. rock to be pulverized instead of a purely rolling or grinding action, as is usual: to the immediate removal of any pulverized material which is crushed to the required fineness, leavin the unfinished residue of the rock to be 'rther reduced without the obstruction of the pulverized material: also to the means whereby the rods by which the pulverizing is effected are carried up the inner side of the tumbler that they may fall over one another, instead of merely sliding and collecting round the interior of the rotatin body.

As the material is screened throughout the entire length of the cylinder, the axis of that cylinder need not be inclined, and the material to be pulverized is delivered through both ends of the tumbler, and is projected well toward the middle of it, so as to insure reasonable distribution of the material to be ground over the length of the pulverizing rods.

There are .other incidental features of construction to which attention is drawn in the following specification, reference being made to the drawings by which it is accompanied, in which:

Fig. 1 is a vertical longitudinal section through the machine.

Fig. 2 is an end elevation of the machine, the end casing being removed as on the line 2-2 in Fig. 1.

Fig.3 is a section of the upper part, belng on the line 3-3 in Fig. 1.

Fig. 4 is a perspective view showing the inner side of one of the screen frames.

' Fig. 5 is an end elevation showing a bafile or chute delivering the broken rock from the ends.

Figs. 6, 7, 8 and 9 show in outline various forms of the rod group frames, and

'Figs. 10 and 11 show in longitudinal and cross section a modification in the driving means.

In these drawings 2 represents the shaft of thepulverizer, which is rotatably mounted in bearings on a suitable frame 3.

Securely keyed on this shaft 2 are hexagonal centre pieces 4, on which the ends of the crushing and screening mill are built up. The hubs 5 of these centre pieces .4 are projected inward toward one another from the inner'plane of the hexagonal portions 4, the arms 6 by which the parts 4 and 5 are connected together being projected inward from 4, so as to leave a central opening through which the rock or ore to be pulverized may be delivered.

The outer edges of the hexagonal centre piece 4 have outward flanges, and to each flanged edge is securely bolted the corresponding flange of a segment 7, the inner edges of which segment conform to the sides of the hexagon that the segments may be bolted to one another as well as to the centre piece 4 and form a circular end for the screening cylinder to be described, as the outer edge of each segment 7 conforms to the circle of that cylinder,

Projected inward from the central portion of each segment 7 is a circular ring 8, forming a support for each end of the bars 10 between which the pulverizing of the rock is effected within the screenin c linder. The inside of each ring 8, on w ic the bars 10 rest, is scalloped, as-at 9, (see Figs. 2 and 3). s

A group oflrods'lO is carried between each corresponding pair of rings 8 of the o posite ends, the rods being passed within t e su portlng rings through a hand hole 11 in the outer part of each se ment within the circle of the ring 8, which hand hole is closable with a door 12 secured by studs and nuts on the outer side.

That portion,.. vvhich connects the rings 8 to the end plate of the segment, is apertured,

as at 13, to permit the rock to fall freely from the rods within each supporting ring, I

but no aperture is in the si e 'of the ring which is toward the central aperture 14, as

' connecting bars between them in a manner to be described are screen carrying frames composed of longitudinal bars 18 connected together at each. end and at intervals apart throughout the length by cross rails 19, which are curved to the circle of the end segments. These frames 18, 19 are preferably of wood.

On the inner side of each frame a wire mesh screen 20 is mailed, to the longitudinal 'bars 18 and end cross rails only, through strips of felt, and these frames with their screen are secured by screw bolts to the end segments 7 and by clamps 22 to the longitudinal bars 15. The clamps 22 extend across the .joint of the longitudinal bars 18 of adjacent frames and are secured at their midlength by tap bolts "to the bar 15, the ends of the clamp being downwardly turned to engage the inner edges of the longitudinal bars 18.

The spaces between the bar supporting rings 8 are closed by triangular plates 23, the bases of which are secured at 24 to the segments 7 of the ends and the apices are directed angularly outward from the shaft 2. These are designed to deliver the rock toward the midlength of the pulverizing bars form a hopper from which the pulverized The revolving tumbler of the mill and its cylindrical screen are enclosed within a suitable casing 25, the bottom sides of which are sloped, as at 26, toward the middle to material which passes through the screen is delivered in any convenient manner.

When the mill is rotated the bars 10 in the concentrically disposed groups ofsupporting rings 8, instead of merely rolling 1n contact with one another within the rings 8,

' as they would do were there no scallops or inequalities in the circle ofthese rings, are retained in the scallops 9 until an angle is attained where the scallops can no longer retain the upper outer bar and it falls from the scallops in which it lies, and tumbles successively over the upper line of bars in the group, being followed successively by the other bars of the upper layer.

This tumbling action of the bars 10, instead of the uncertain and ineffective rolling or grinding action of them on one another,

is what is largely depended on to give a higher efiiciency in the pulverizi ng and particularly with hard-rock that may require impact as well as crushing to reduce it to the required fineness.

The rock, broken to approximately onequarter inch mesh, is fed through a spout 27 Which projects into the central openingof each end surrounding the shaft 2, and falls within the circle'of the'groups of rods 10 supported in the rings 8 and extending between them, being delivered toward the medial portion of the rods between the supports by the angle plates .23.

As the rock is broken and pulverized by the combined tumbling and rolling action of the bars 10, the pulverized material falls through the bars on to the inner surface of the screens 20. Such as is sufliciently fine will pass through the screen and the residue is carriedup by the inwardly projecting bars 15 and is thrown again on to the surface of the bars 10.

The essential features of this machine are that it is continuous in its delivery that as soon as the material is broken sufficiently fine to pass through the screens, it is withdrawn from the material under treatment and does not impede the pulverizing action on the residue: that, under the restraining influence of the scallops 9, the groups of rods 10 do not merely slide or roll around the inner surface of their supporting rings 8 but are carried up until the maximum limiting angle of stability is passed when they tumble over one another to the lower side. In that tumbling action combined with the rolling or grinding movement of the bars on one another the efliciency of the pulverizer is largely dependent. I

The sectional construction adopted enables the weight of the individual parts to be limited to what is considered desirable for transportation by pack animals where such is necessary, and the parts can readily be put together at the mine with the skilled labour there available.

The scallops 9, around the inner surface of the rod supporting frames 8, are designed to prevent the rods from merely sliding en masse around the inner sides of the rings 8,

while the pulverizer rotates, as with a smooth surface they would certainly do. In.

practice it maynot be necessaryto continue the scallops all the way round, but a few rod retaining scallops or projections may alternate with uninterrupted surfaces, as shown in Fig. 6, or the desired result of preventing sliding movement of the rod groups en masse may be attained by making the frames 8 within which the rods are supported, triangular, square or polygonal, as shown in Figs. 7, 8 and 9.

Although the mill is,described so far as supported on and driven by a central shaft,

themanner of supporting and driving is immaterial so long as the essential features of the invention are retained.

' If, as shown in Figs. 10 and 11, the circular ends are roduced, as at 30, beyond the diameter of t e screen cylinder, and each end is carried on roller wheels 31, one or both of these ,roller wheels at each end may be driving wheels. This manner of supporting and driving will enable the central portion 4 of each end with its hub 5 and arms Gto be dispensed with, and an unobstructed central aperture will be available through which the ore ma be fed and effectively distributed over the ength of the pulverizing rods b distributing chutes 32.

from the horizontal, at which angle the ma-- terial will readily slide off the upper angled surface of the bar.

It is, therefore, desirable, for the proper distribution of the material over the groups of bars, that this distribution be efiected throughout a greater are of movement than the forty-five degrees (45) referred to.

This desirable result is attained by angling or directing the inner edge of each. bar 15 toward the direction of rotation of the pulverizer, as at 21, whereby the material will be carried by the forwardly directed edge 21 of the bar and gradually distributes on the rods 10 through a further angle of ap-:

proximately ninety degrees (90), and more .rods 10 as they fal will be effected bythe over one another. Having now particularly described my invention, I hereb declare that what claim as new and esire to be protected in by Letters Patent, is:

1. A rod pulverizer, com rising ends spaced apart and secured toget er, each end having a corresponding series of rod supporting frames secured to it to project from its inner face and support the rods intermediate their ends, t e inner surfaces of which frames have means for preventing the rods moving collectively round the frame as the rods rotate and apertured between the rod supports and the ends to provide escape of the material from that space,

efi'ective pulverizing a group of freely movable rods supported in the-corresponding frame of each end and extending between them, means forrotating the ends with their supported rods, means for delivering the material to be pulverized on the upper surfaces of the rods in the several groups and means for screening the material as it falls from the rods.

2. A rod pulverizer, comprising centrally apertured ends each having a corresponding series ofrod supporting rames projecting from its inner face, the inner surfaces of which frames have means preventing the rods sliding collectively round the frame as the ends rotate and each end made up of'a central apertured polygon and a series of.

symmetrical ,seg lents each secured to aside of the polygon and to the adjacent segments, each segment including one rod supporting frame, longitudinal bars extending between the ends and secured between the segments,

the longer dimension of the cro'ss section of- .each bar projecting inward, a group of between the ends and suprods extendin frame thereof, a series of ported in eac screen segments secured between the' ends and outside the longitudinal bars and -se-" cured to each, means for delivering the material to be pulverized through the central apertures of the ends on to the upper surface of each'group of rods, and means for rotating the ends with their connected rods and screens.-

3. A rod pulverizer, comprising centrally. apertured ends each having a corresponding series of rod supporting frames projecting fromits inner face, the inner surfaces of which frames have means preventing the rods sliding collectively round the frame as the ends rotate and each end made up of a series of symmetrical segments each including one red supporting frame, longitudinal'bars extending between the ends and secured to the segments thereof, each bar having a projection along its inner edge extending toward .the direction of rotation, a group of'rods extending between the ends and supported in each frame thereof, a series of screen segments secured between the ends and outside the longitudinal bars and secured to each, means for delivering the material to be pulverized through the central apertures of-the ends on to the upper surface of each group of rods, and means for rotating the ends with their connected rods and screens.

In testimony whereof I aifix my signature.

CARL s. WILLIS.

llO 

